It was a long time ago when we were "kids"... but it worked.
The thimble fit pretty well inside the spring, and wrapped in duct tape the spring formed a tube, which went down to a hole punched in the tube part of the snorkel. Mouth piece of snorkel was ripped off, and covered with a bottle cap. The whole thing worked pretty well actually, well for what it was at least.
We also made a "hooka" pipe out of a stethoscope (no water, but two person).
Think this one wins though :
When I was a kid we used to like to crack open fireworks, and make bigger, louder fireworks...
I used to make an electronic fuse by cracking open Christmas lights (the little ones) so that the fillament was exposed to the gun powder, and when you "turned on" the light it would burn out.
I then broke open a remote control car I had, stripped out the circuit board and battery and put them in a little box with two screw sticking out for electrical contacts. I cut out the motor and attached the wires to the screws. Then I hooked the Christmas light ignitor up to the contacts. When you took the remote and pressed forward it would try to power the electric motor and burn out the light bulb instead setting off the fireworks we hooked up to it. Home made remote detonator from kids toys and holiday decorations
Worked well, but not that big of a range.